Tongling College

Wusong, China

Tongling College

Wusong, China

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Yongjiang D.,Tongling College
Advanced Materials Research | Year: 2013

Heuristic clustering method based on local information is introduced, and then the label propagation method based on local information is summarized, and the problem of the iterative process and using a random strategy to select a node belongs to the cluster structure are analyzed. Label propagation algorithm base on the similarity of node attributes is improved. At last, the experiments are used to help to discover the efficient and availability of the algorithm, and put the algorithm into preliminary application. © (2013) Trans Tech Publications, Switzerland.


Wen C.,Tongling College
2011 International Conference on Electrical and Control Engineering, ICECE 2011 - Proceedings | Year: 2011

The generation of frequent itemsets is the key of association rules mining. Based on bit vectors and its intersection operation of the DLG ideas, this paper presents a new k-frequent itemsets generation algorithm based on bit matrix. The algorithm scans the database only once, using bit matrix of alternative association graph to store, constructing screening conditions to reduce the validation of candidate frequent itemsets in long patterns of frequent itemsets generated effectively. Compared with DLG, experimental results show the effectiveness and accuracy of this algorithm. © 2011 IEEE.


Wen C.,Tongling College
International Journal of Security and its Applications | Year: 2015

The traditional location privacy protection means mainly employs reliable central server framework, and it mainly applies the anonymous region meeting the k-anonymity at the anonymous server to replace the real location of users. However, the disadvantages of the central server, such as being attacked easily, high communication cost, etc. are disclosed accordingly. In addition, the anonymous method of most locations is oriented for the European style, and it is not applicable to the road network. In order to solve the above problem, virtual user group-based centerless server framework is proposed for solving the location privacy protection in road network. This algorithm mainly forms the virtual user group with several virtual users in several road segments of the road network, and replaces the real position of the user with a certain point in the section, so as to realize the k-anonymity of user position with the increment nearest neighbor query. Since the algorithm adopts the accurate increment nearest neighbor query method, it guarantees the service quality. The experiment proves that the algorithm can reduce the communication cost effectively and improve the application safety. © 2015 SERSC.


Zhang J.,Tongling College | Wang J.,Tongling College
Zhongguo Jixie Gongcheng/China Mechanical Engineering | Year: 2010

A method of extrusion process multiple-objective optimization was proposed based on numerical simulation and genetic algorithm. The extrusion force and the damages of the final forging were considered into the multiple-objective function. The hot extrusion forming was simulated by Deform software. The data of extrusion force and damages were acquired by designing the friction factor, extrusion speed and extrusion ratio. The mathematics models of deformation force and damages were established via multivariable nonlinear regressing. The evaluation model of multiple-objective design optimization was constructed by using the weighting function method. The optimal solution of the extrusion process parameters was calculated by an improved genetic algorithm. A case study was conducted for a thermal brass rod hot extrusion process, and the optimal parameters were obtained.


Zhu Y.,Hefei University of Technology | Zhu Y.,Tongling College | Kan C.,Hefei University of Technology
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2014

In the wind power generation system, wind power generators need to accurately control the torque according to the torque command from the master control system. In the traditional control system, the current command is directly calculated according to the torque command and then it is controlled by the current closed-loop. However, because of the influence of the parameters, the torque control accuracy is lowered as a result. For this reason, this paper proposes a stator flux and electromagnetic torque observer for the permanent magnet synchronous motor (PMSM) based on a full order sliding mode observer. Compared with the traditional voltage model based flux observer, the proposed observer has overcome the problems of integral initial value and integral drift. Compared with the traditional current model based flux observer, the proposed observer is independent of the parameters of the inductance and permanent magnet flux linkage. Based on the observed stator flux, the electromagnetic torque can be accurately observed. In addition, the torque control accuracy can be greatly improved by the torque closed-loop. Simulation and experimental results have verified the effectiveness of the proposed algorithm.


Zhang J.,Tongling College | Chen K.,Hefei University of Technology
Jisuanji Fuzhu Sheji Yu Tuxingxue Xuebao/Journal of Computer-Aided Design and Computer Graphics | Year: 2010

An adaptive ant colony algorithm (AACA) is established to solve the problems of long computing time and stagnation behavior of the basic ant colony optimization which is applied for concurrent design tasks planning and scheduling. A path selection mechanism is designed for the ant path diversity. The path pheromones is updated according to a dynamic factor of objective function values. Some ants are replaced at a dynamic rate with mutated ants, which leads to the evolution of the colony. Case simulation results show that the AACA has a excellent ability of global optimization and high search efficiency, and can settle the contradiction between convergence speed and stagnation behavior.


Wen C.,Tongling College
Cybernetics and Information Technologies | Year: 2015

Check-in service, being one of the most popular services in Mobile Social Network Services (MSNS), has serious personal privacy leakage threats. In this paper check-in sequences of pseudonym users were buffered, and a bit matrix for buffered check-in sequences was built, which can achieve privacy guarantee of k-anonymity. The method guarantees that the number of lost check-in locations is minimized while satisfying users' privacy requirements. Besides, it also reduces the cost of finding a trajectory k-anonymity set. At last, the results of a set of comparative experiments with (k, δ)-anonymity on real world datasets show the method accuracy and efficiency.


Wen C.,Tongling College
International Journal of u- and e- Service, Science and Technology | Year: 2014

Check-in service as one of the most popular services in mobile social network services (MSNS), has serious personal privacy leakage threats. In this paper, check-in sequences of pseudonym users were buffered, and association graph for buffered check-in sequences was built, which can achieve a privacy guarantee of k-anonymity. The method guarantee the number of lost check-in locations is minimized while satisfying users' privacy requirements, it is also reduces the cost of finding trajectory k-anonymity set. At last, the results of a set of comparative experiments with (k,δ) - anonymity on real world datasets show the method's accuracy and effectiveness. © 2014 SERSC.


Sun Y.,Tongling College | Sun Y.,Tongji University | Zhou S.,Tongji University | Zhuang L.,Tongji University
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2011

The soils inside a foundation pit undergo vertical unloading during excavation, which almost always causes residual stress. In order to study the impact of residual stress on the passive pressure and shear strength of soils, a static model loading-unloading test using sands is conducted. Experimental results show that the stress in sands does not reduce at the initial stage of unloading and there is residual stress even after the load is completely removed. Using normalizations of factors that affected the distribution of residual stress, a function between the residual stress coefficient ξ and unloading ratio R is established. Base on the characteristics of soils, a formula for calculating the residual stress of foundation pit is proposed. The calculated shear strength in passive zone agrees well with the measured values.


Zhu Y.,Hefei University of Technology | Zhu Y.,Tongling College | Zhang X.,Hefei University of Technology | Liu S.,Hefei University of Technology
2011 International Conference on Consumer Electronics, Communications and Networks, CECNet 2011 - Proceedings | Year: 2011

The Brushless Doubly-Fed Machine (BDFM), which removes the brush and slip ring, improves security and reliability. The BDFM is proposed to have a bright prospect as an AC drive system or variable-speed constant-frequency power generation system. Vector control is widely studied in the BDFM, but the information of rotor speed and position must be obtained. This paper presents speed sensorless vector control strategy for BDFM double synchronous speed two-axis rotating coordinate mathematical model based on model reference adaptive speed identification theory. Vector control model in Matlab/Simulink environment is designed with popov stability theory. The simulation results verify that this system has good stationary and dynamical property. © 2011 IEEE.

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